1. Field of the Invention
This invention relates to a vehicle-installed head-up display device, and more particularly to a vehicle-installed head-up display device which reflects a displayed image by a translucent reflecting means arranged in a visual field ahead of a driver and permits the driver to recognize a displayed image visually as a virtual image ahead of a windshield.
2. Description of the Related Art
An example of such a device is shown in FIG. 10. In FIG. 10, a light-emitting display 111 of e.g. a liquid crystal or fluorescent display tube is installed in a dashboard (not shown) so that its displaying screen is oriented forward of the vehicle. A reflecting mirror 113 is arranged oppositely to and at an angle formed with the displaying screen of the display 11. The light of the image displayed on the display 111 is incident on the reflecting mirror 113 through an enlarging optical system 112 such as a Fresnel lens.
The reflecting mirror 113 reflects the light of the displayed image toward the inner face on the side of a passenger room of a windshield (front glass) 20 of the vehicle. The inner face is coated with a translucent reflecting film 21 capable of increasing the reflectance of the inner face as the occasion demands to raise the brightness of the displayed image reflected by the reflecting mirror 113. Therefore, the driver can see the displayed image which is imaged far by the enlarging optical system 112 as an image 111xe2x80x2 and reflected by a translucent reflecting film 21 as an enlarged virtual image 111xe2x80x3 far ahead of the windshield.
Although not shown, the light emitting display 111, enlarging optical system 112 and reflecting mirror 113 are installed as a displaying unit within a single case. Its outer size depends on the size (viewing angle) of the displayed image, displaying distance by the enlarging optical system and a visible range 30. The visible range must be assured within an eye range 31 which varies according to a driving posture and physics of the driver. Assuming that the displaying distance is 2-3 m, in order to cover 95% to 99% of the eye range, the display unit must have an increased outer size and hence is difficult to be arranged in a dashboard having a limited space.
In order to obviate such an inconvenience, traditionally, since the visible range of a driver does not move so greatly during running, only a certain visible range is assured. For example, as shown in FIG. 11, an adjusting mechanism is added which serves to move the reflecting mirror 113 linearly so that its distance from the displaying screen of the display 111 varies. Otherwise, as shown in FIG. 12, another adjusting mechanism is added which serves to rotate the reflecting mirror 113 so that its angle formed with the display 111 varies. Thus, the visible range 30 can be moved within the eye range 31.
As another example of such a device, the structure as shown in FIG. 13 was proposed. In FIG. 13, a light-emitting display 211 of e.g. a liquid crystal or fluorescent display tube is arranged within a dashboard of the vehicle (not shown) so that its displaying screen is oriented toward the rear of the vehicle. A reflecting mirror 212 is arranged apart from the display 211 so that the reflecting face is opposite to the displaying screen. The reflecting mirror 212 serves to reflect the light of the displayed image (hereinafter referred to as xe2x80x9cimage lightxe2x80x9d) toward the displaying screen of the display 211. The reflecting mirror 212 may be a concave mirror.
A translucent reflecting plate 213 is arranged between the display 211 and the reflecting mirror 212. The translucent reflecting mirror 213 may be a half mirror which is inclined at a prescribed angle so as to transmit the image light from the display 211 and to reflect the light of the displayed image reflected by the reflecting mirror 212 toward the inner face on the side of a passenger room of a windshield (front glass) 20 of the vehicle through the opening above the dash board. The inner face maybe coated with a translucent reflecting film 21 capable of increasing the reflectance of the inner face as the occasion demands to raise the brightness of the displayed image reflected by the reflecting mirror 213.
In accordance with such a configuration, the driver can visually recognize the displayed image on the display finally reflected by the windshield 20 as a virtual image 211xe2x80x3 which is imaged as a virtual image enlarged by the curvature of the windshield at a position corresponding to the sum of the distances between the display 211 and the reflecting mirror 212, between the reflecting mirror 212 and the translucent reflecting mirror 213 and between the reflecting mirror 213 and the windshield 20.
However, in order to improve installation capability in the vehicle, any of the proposals cannot miniaturize the display device without reducing the size of the displayed image. Further, where the displayed image with a further increased size is required, an existing unit having only the function of adjusting the eye range cannot satisfy the requirement. Namely, an increased size of the unit which cannot be installed in the vehicle is necessary.
In view of the above circumstance, an object of this invention is to provide a vehicle-installed head-up display device which can be further miniaturized and improve installation capability in a vehicle.
Another object of this invention is to provide a vehicle-installed head-up display device which can display a large image without being up-sized.
In accordance with this invention, there is provided a a vehicle-installed head-up display device comprising:
final reflecting means located in a field of view ahead of a driver""s seat, the final reflecting means being translucent;
displaying means capable of selectively displaying one of first and second images by light emission on a signal displaying screen;
first reflecting means for reflecting light of a displayed image toward a first reflective area of the final reflecting means;
second reflecting means for reflecting light of the displayed image toward a second reflective area of the final reflecting means, the second reflective area being adjacent to the first reflective area; and
optical path exchanging means for exchanging an optical path so that when the first image is displayed by the displaying means, only the light of the first image reflected by the first reflecting means is incident on the first reflective area, whereas when the second image is displayed by the displaying means, only the light of the second image is incident on the second reflective area, wherein
the first and second images one of which is selectively displayed are reflected by the first reflective area and the second reflective area of the final reflecting means so that a driver can visually recognize these images as virtual images ahead of a windshield.
In this configuration, the two images, one of which is selectively displayed on the single displaying screen of the displaying means, are reflected by the translucent reflecting means arranged in the field of view ahead of the driver""s seat and can be visually recognized by the driver.
In a preferred embodiment, selective display of the first and second displayed images is made in a period shorter that the afterimage of eyes, and in synchronism with the selective display, the optical path is exchanged by the optical path changing means whereby the displayed images are visually recognized as a single virtual image.
In this configuration, the two displayed images can be visually recognized as a single virtual image by the driver.
In accordance with this invention, there is provided a vehicle-installed head-up display device comprising:
final reflecting means located in a field of view ahead of a driver""s seat, the final reflecting means being translucent;
displaying means capable of selectively displaying one of two images by light emission on a signal displaying screen;
first reflecting means for reflecting light of a displayed image toward a first reflective area of the final reflecting means;
second reflecting means for transmitting a part of light of the displayed image and reflecting the remainder of the light toward a second reflective area of the final reflecting means, the second reflecting means being located between the first reflecting means and the displaying means, the second reflective area being adjacent to the first reflective area, and the second reflecting means being translucent;
first shutter means for controlling transmission/non-transmission of the light of the displayed image reflected by the first reflecting means; and
second shutter means for controlling transmission/non-transmission of the light of the displayed image reflected by the second reflecting means, wherein
one of the first shutter means and second shutter means is opened and the other thereof is closed according to each image selectively displayed by the displaying means, and the displayed image transmitted by the first shutter means or the second shutter means is reflected by the first reflective area or the second reflective area so that a driver can visually recognize the displayed image as a virtual image ahead of a windshield.
In this configuration, the two images, one of which is selectively displayed on the single displaying screen of the displaying means, are reflected by the first and second reflecting means and thereafter reflected by the translucent reflecting means arranged in the field of view ahead of the driver""s seat and can be visually recognized by the driver.
In a preferred embodiment,
the first shutter means is located between the first reflecting means and the first reflective area of the final reflecting means, and
the second shutter means is located between the second reflecting means and the second reflective area of the final reflecting means.
In this configuration, these first and second shutter means can be designed as a single shutter means which can be alternately opened and closed apparently.
In a preferred embodiment, the head-up display device comprises enlarging optical means located between the displaying means and the second reflecting means.
In this configuration, the two displayed images are equally enlarged and imaged at equal far positions.
In a preferred embodiment,
the two displayed images are upper and lower elements divided from a single image, when the upper element is displayed by the displaying means, the first shutter means is closed and the second shutter means is opened, whereas the lower upper element is displayed by the displaying means, the first shutter means is opened and the second shutter means is closed, and
relative positions of the first reflecting means and the second reflecting means are located so that these upper and lower elements are imaged as an single integral virtual image.
In this configuration, the displayed image of information having a size twice as large as the image of information which can be once displayed by the displaying means can be visually recognized by the driver.
In a preferred embodiment, a lower end point of the displayed image reflected by the first reflecting means and an upper point of that reflected by the second reflecting means accord to each other in their reflecting optical paths.
In this configuration, continuity of the two displayed images can be kept.
In a preferred embodiment, the head-up display device further comprises:
means for adjusting the directions of the light of the displayed images reflected by the first reflecting means and the second reflecting means toward the final reflecting means so that the position of the virtual image to be visually recognized ahead of the windshield is adjusted; and
means for adjusting the position of the shutter means so that the transmission/non-transmission of the light of the displayed images can be controlled.
In this configuration, the visible range can be adjusted within the eye range without disordering the relative positions of the two displayed images.
In accordance with this invention, there is provided a vehicle-installed head-up display device comprising:
final reflecting means located in a field of view ahead of a driver""s seat, the final reflecting means being translucent;
displaying means capable of selectively displaying one of first and second-images by light emission on a signal displaying screen;
intermediate reflecting means for reflecting light of the displayed image;
first translucent reflecting means for reflecting light of the displayed image toward a first reflective area of the final reflecting means, the first translucent reflecting means being located between the displaying means and the intermediate reflecting means;
second translucent reflecting means for reflecting light of the displayed image toward a second reflective area of the final reflecting means, the second reflective area being adjacent to the first reflective area, the second translucent reflecting means being located between the displaying means and the intermediate reflecting means; and
first shutter means for controlling transmission/non-transmission of the light of the displayed image reflected by the first translucent reflecting means; and
second shutter means for controlling transmission/non-transmission of the light of the displayed image reflected by the second reflecting means, wherein
one of the first shutter means and second shutter means is opened and the other thereof is closed according to each image selectively displayed by the displaying means, and the displayed image transmitted by the first shutter means or the second shutter means is reflected by the first reflective area or the second reflective area so that a driver can visually recognize the displayed image as a virtual image ahead of a windshield.
In this configuration, the two displayed images are finally reflected by the final translucent reflecting means are imaged at a position far ahead of the windshield corresponding to the sum of the distances from the displaying means and the intermediate reflecting means, from the intermediate reflecting mans to the first and second reflecting means and from the first and second reflecting means to the final translucent reflecting means. The driver can visually recognize these virtual images.
In a preferred embodiment, the intermediate reflecting means is a concave mirror. Therefore, the two images are equally enlarged.
In a preferred embodiment, the first shutter means is located between the first translucent reflecting means and the first reflective area of the final reflecting means, and
the second shutter means is located between the second translucent reflecting means and the second reflective area of the final reflecting means.
In this configuration, these first and second shutter means can be designed as a single shutter means which can be alternately opened and closed apparently.
The above and other objects and features of the invention will be more apparent from the following description taken in conjunction with the accompanying drawings.